diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d3ac58dc275f..185711a852b0 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2415,6 +2415,8 @@ struct drm_i915_private {
 	unsigned int active_crtcs;
 	/* minimum acceptable cdclk for each pipe */
 	int min_cdclk[I915_MAX_PIPES];
+	/* minimum acceptable voltage for each pipe */
+	u8 min_voltage[I915_MAX_PIPES];
 
 	int dpio_phy_iosf_port[I915_NUM_PHYS_VLV];
 
diff --git a/drivers/gpu/drm/i915/intel_cdclk.c b/drivers/gpu/drm/i915/intel_cdclk.c
index 2a0cc9aafa5a..0f5f2ce4bd3e 100644
--- a/drivers/gpu/drm/i915/intel_cdclk.c
+++ b/drivers/gpu/drm/i915/intel_cdclk.c
@@ -1661,6 +1661,12 @@ static void cnl_set_cdclk(struct drm_i915_private *dev_priv,
 	mutex_unlock(&dev_priv->pcu_lock);
 
 	intel_update_cdclk(dev_priv);
+
+	/*
+	 * Can't read out the voltage :( So let's
+	 * just assume everything is as expected.
+	 */
+	dev_priv->cdclk.hw.voltage = cdclk_state->voltage;
 }
 
 static int cnl_cdclk_pll_vco(struct drm_i915_private *dev_priv, int cdclk)
@@ -1930,6 +1936,42 @@ static int intel_compute_min_cdclk(struct drm_atomic_state *state)
 	return min_cdclk;
 }
 
+/*
+ * Note that this functions assumes that 0 is
+ * the lowest voltage value, and higher values
+ * correspond to increasingly higher voltages.
+ *
+ * Should that relationship no longer hold on
+ * future platforms this code will need to be
+ * adjusted.
+ */
+static u8 cnl_compute_min_voltage(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct intel_crtc *crtc;
+	struct intel_crtc_state *crtc_state;
+	u8 min_voltage;
+	int i;
+	enum pipe pipe;
+
+	memcpy(state->min_voltage, dev_priv->min_voltage,
+	       sizeof(state->min_voltage));
+
+	for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
+		if (crtc_state->base.enable)
+			state->min_voltage[i] = crtc_state->min_voltage;
+		else
+			state->min_voltage[i] = 0;
+	}
+
+	min_voltage = 0;
+	for_each_pipe(dev_priv, pipe)
+		min_voltage = max(state->min_voltage[pipe],
+				  min_voltage);
+
+	return min_voltage;
+}
+
 static int vlv_modeset_calc_cdclk(struct drm_atomic_state *state)
 {
 	struct drm_i915_private *dev_priv = to_i915(state->dev);
@@ -2086,7 +2128,9 @@ static int cnl_modeset_calc_cdclk(struct drm_atomic_state *state)
 
 	intel_state->cdclk.logical.vco = vco;
 	intel_state->cdclk.logical.cdclk = cdclk;
-	intel_state->cdclk.logical.voltage = cnl_calc_voltage(cdclk);
+	intel_state->cdclk.logical.voltage =
+		max(cnl_calc_voltage(cdclk),
+		    cnl_compute_min_voltage(intel_state));
 
 	if (!intel_state->active_crtcs) {
 		cdclk = cnl_calc_cdclk(0);
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index adf51b328844..f707134b4f65 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2525,6 +2525,13 @@ bool intel_ddi_is_audio_enabled(struct drm_i915_private *dev_priv,
 	return false;
 }
 
+void intel_ddi_compute_min_voltage(struct drm_i915_private *dev_priv,
+				   struct intel_crtc_state *crtc_state)
+{
+	if (IS_CANNONLAKE(dev_priv) && crtc_state->port_clock > 594000)
+		crtc_state->min_voltage = 2;
+}
+
 void intel_ddi_get_config(struct intel_encoder *encoder,
 			  struct intel_crtc_state *pipe_config)
 {
@@ -2624,6 +2631,8 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
 	if (IS_GEN9_LP(dev_priv))
 		pipe_config->lane_lat_optim_mask =
 			bxt_ddi_phy_get_lane_lat_optim_mask(encoder);
+
+	intel_ddi_compute_min_voltage(dev_priv, pipe_config);
 }
 
 static bool intel_ddi_compute_config(struct intel_encoder *encoder,
@@ -2650,6 +2659,8 @@ static bool intel_ddi_compute_config(struct intel_encoder *encoder,
 			bxt_ddi_phy_calc_lane_lat_optim_mask(encoder,
 							     pipe_config->lane_count);
 
+	intel_ddi_compute_min_voltage(dev_priv, pipe_config);
+
 	return ret;
 
 }
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 32e7cca52da2..83024956a74d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5938,6 +5938,7 @@ static void intel_crtc_disable_noatomic(struct drm_crtc *crtc,
 
 	dev_priv->active_crtcs &= ~(1 << intel_crtc->pipe);
 	dev_priv->min_cdclk[intel_crtc->pipe] = 0;
+	dev_priv->min_voltage[intel_crtc->pipe] = 0;
 }
 
 /*
@@ -11304,6 +11305,8 @@ intel_pipe_config_compare(struct drm_i915_private *dev_priv,
 	PIPE_CONF_CHECK_CLOCK_FUZZY(base.adjusted_mode.crtc_clock);
 	PIPE_CONF_CHECK_CLOCK_FUZZY(port_clock);
 
+	PIPE_CONF_CHECK_I(min_voltage);
+
 #undef PIPE_CONF_CHECK_X
 #undef PIPE_CONF_CHECK_I
 #undef PIPE_CONF_CHECK_P
@@ -11964,6 +11967,9 @@ static int intel_modeset_checks(struct drm_atomic_state *state)
 		DRM_DEBUG_KMS("New cdclk calculated to be logical %u kHz, actual %u kHz\n",
 			      intel_state->cdclk.logical.cdclk,
 			      intel_state->cdclk.actual.cdclk);
+		DRM_DEBUG_KMS("New voltage calculated to be logical %u, actual %u\n",
+			      intel_state->cdclk.logical.voltage,
+			      intel_state->cdclk.actual.voltage);
 	} else {
 		to_intel_atomic_state(state)->cdclk.logical = dev_priv->cdclk.logical;
 	}
@@ -12532,6 +12538,8 @@ static int intel_atomic_commit(struct drm_device *dev,
 	if (intel_state->modeset) {
 		memcpy(dev_priv->min_cdclk, intel_state->min_cdclk,
 		       sizeof(intel_state->min_cdclk));
+		memcpy(dev_priv->min_voltage, intel_state->min_voltage,
+		       sizeof(intel_state->min_voltage));
 		dev_priv->active_crtcs = intel_state->active_crtcs;
 		dev_priv->cdclk.logical = intel_state->cdclk.logical;
 		dev_priv->cdclk.actual = intel_state->cdclk.actual;
@@ -15042,6 +15050,7 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 		}
 
 		dev_priv->min_cdclk[crtc->pipe] = min_cdclk;
+		dev_priv->min_voltage[crtc->pipe] = crtc_state->min_voltage;
 
 		intel_pipe_config_sanity_check(dev_priv, crtc_state);
 	}
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 772521440a9f..6c1da88b5fef 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -34,6 +34,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 					struct intel_crtc_state *pipe_config,
 					struct drm_connector_state *conn_state)
 {
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
 	struct intel_digital_port *intel_dig_port = intel_mst->primary;
 	struct intel_dp *intel_dp = &intel_dig_port->dp;
@@ -87,6 +88,8 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
 
 	pipe_config->dp_m_n.tu = slots;
 
+	intel_ddi_compute_min_voltage(dev_priv, pipe_config);
+
 	return true;
 }
 
@@ -307,6 +310,8 @@ static void intel_dp_mst_enc_get_config(struct intel_encoder *encoder,
 	intel_dp_get_m_n(crtc, pipe_config);
 
 	intel_ddi_clock_get(&intel_dig_port->base, pipe_config);
+
+	intel_ddi_compute_min_voltage(dev_priv, pipe_config);
 }
 
 static int intel_dp_mst_get_ddc_modes(struct drm_connector *connector)
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 765a737700c5..002894b13d69 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -386,6 +386,8 @@ struct intel_atomic_state {
 	unsigned int active_crtcs;
 	/* minimum acceptable cdclk for each pipe */
 	int min_cdclk[I915_MAX_PIPES];
+	/* minimum acceptable voltage for each pipe */
+	u8 min_voltage[I915_MAX_PIPES];
 
 	struct intel_shared_dpll_state shared_dpll[I915_NUM_PLLS];
 
@@ -739,6 +741,8 @@ struct intel_crtc_state {
 	 */
 	uint8_t lane_lat_optim_mask;
 
+	u8 min_voltage;
+
 	/* Panel fitter controls for gen2-gen4 + VLV */
 	struct {
 		u32 control;
@@ -1294,6 +1298,8 @@ void intel_ddi_clock_get(struct intel_encoder *encoder,
 			 struct intel_crtc_state *pipe_config);
 void intel_ddi_set_vc_payload_alloc(const struct intel_crtc_state *crtc_state,
 				    bool state);
+void intel_ddi_compute_min_voltage(struct drm_i915_private *dev_priv,
+				   struct intel_crtc_state *crtc_state);
 u32 bxt_signal_levels(struct intel_dp *intel_dp);
 uint32_t ddi_signal_levels(struct intel_dp *intel_dp);
 u8 intel_ddi_dp_voltage_max(struct intel_encoder *encoder);
